In a pre-recorded interview, played at Bournemouth Crown Court, the alleged victim said Jamieson had been visiting the property and among a group listening to music in the lounge of the shared property when he asked them to turn the volume down.

The victim was punched and, as he tried to get into his room, Jamieson forced his way in, the court heard.

The man said Jamieson had punched him seven times as he robbed him of cash, a phone, computer and small television.

He said Jamieson had taken his bank cards and, when he refused to tell him his PIN numbers, he had threatened to kill him, saying he had a knife.

“He said: ‘Unless you give me the numbers I’m going to kill you’,” the alleged victim told police. He claimed Jamieson had added: “I have a knife and it would be quite easy to do it.”

The shocked pensioner was then forced to perform a sex act, now classed as rape, the court heard. When he still refused to tell Jamieson his PIN numbers, the teenager threatened to rape him again, it was alleged, and after a “scuffle” the man gave him false numbers.

In the morning he noticed his carving knife was missing and later told police: “It was a nightmare.”

Jamieson denies rape and sexual assault on January 25 this year.

James Newton-Price, prosecuting, said Jamieson had been spotted on CCTV trying to use one of the bank cards at a cashpoint at Tesco on Charminster Road.

He told jurors how Jamieson had tried to sell the stolen laptop at the Golden Supermarket on the same road.

Mr Newton-Price described the victim as “frail” and said he had been attacked in “humiliating circumstances”